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BD1754HFN

Datasheet

TSZ02201-0G3G0C200060-1-2

10.Dec.2015 Rev.002

www.rohm.com

© 2012 ROHM Co., Ltd. All rights reserved.

TSZ22111･15･001

Application Information

1. Description of Operations

(1) UPIC (= Uni-Port Interface Control) interface

BD1754HFN has a single-line digital control interface (UPIC) that can control the power ON/OFF and LED current

value through the EN pin. The LED current decreases by one step depending on the number of rising edges. When

the minimum output current is reached (64 rising edges), the next rising edge changes the output current to the

maximum value at startup time. To maintain any output current, the EN pin must be kept at ‘H’ level. To power OFF,

the EN pin must be kept

at ‘L’ level for more than 1msec.

MAX Current

MAX Current

EN

(Internal)

State

C64

C63

C62

C61

C62

C60

C2

C1

C64

C63

OFF

OFF

MIN Current

OFF

OFF

Figure 10. Brightness Control Method

EN

Figure 11. UPIC Interface

By the following sequence, UPIC can control the current driver for MAX current and OFF state only.

Figure 12. UPIC Interface Usage for MAX current or OFF Only

MAX

Current

MAX

Current

EN

(Internal)

State

C64

C64

OFF

OFF

OFF

OFF

OFF

OFF